Volatile fumigant pad



Feb. 20, 1951 F. H. MAYER VOLATILE FUMIGANT PAD Filed Feb. 14, 1947INVENTOR Patented Feb. 20, 1951 UNITED STATES PATENT OFFICE VOLATILEFUMIGAN T PAD Fred H. Mayer, Portland, Oreg. Application February 14,1947, Serial No. 728,413

2 Claims. 1

This invention relates to insecticides and deodorizing volatile pads, ofthe same general description illustrated and described in my Patent No.2,054,434, dated Sept. 15, 1936, except that by reason of structuralchanges that will be described hereinafter, the rate of volatilizationof the deposits on the fingers f the pad may be selectively variedwithin quite a wide range, which is stated to be the object of thisinvention.

In placing many thousands of the pads of the kind show; the patent, itwas discovered that the rate at which the deposits of volatile materialvolatilize is sharply increased if they are separated from each other bya space of about the width of a finger with its deposit; and that thereis a layer of saturated atmosphere that builds around each surface andeffectively prevents access of fresh atmosphere to the surface ofvolatilizable material except at a slow rate. It has also been proved tomy satisfaction that the layer of gaseous atmosphere created byevaporation tends to cling to and remain in contact with the body ofmaterial from which it was derived and that a fiat pad of deposit builtup on a cardboard. Whether or not it has partial divisions into separatefingers, has a much slower volatilization rate than if actually dividedinto fingers separated from each other by at least the breadth of asingle finger. I take advantage of this discovery by the structure shownin the drawing, in which:

Fig. 1 illustrates a cardboard mounting having six dependent fingerswith heavy coats of insecticide material;

Fig. 2 shows the same structure shown in Fig. 1 but with the card foldedupon itself to place the side boundaries in juxtaposition and in effectto produce a card with a solid one-piece deposit;

Fig. 3 is a plan view of Fig. 2 from the plane 3-3 in that figure;

Fig. 4 is a somewhat enlarged view of Fig. 2 from the plane 4-4illustrating what careful tests have shown to be a fact, that a denselayer of saturated air gathers around a group of coated fingers injuxtaposition; and

Fig. 5 shows an enlarged view of two fingers only, taken from the plane5-5, Fig. 1, illustrating the effect of adequate spacing.

Describing the drawings in greater detail:

Numeral l illustrates a cardboard mounting member upon which dependentfinger-like parts 2, have been cut. In quantity production, this isalways done by a die. Each finger has deposited thereon a deposit 3, ofnaphthalene or other suitable vaporizable insecticide, the actualcomposition of which is not a part of this invention. Such cards arecommonly hung in closets or laid in chests to repel or destroy moths ortheir larvae that would otherwise attack any textile of ani mal fiberthat might be stored therein.

In making and selling these insecticide pads, a

considerable reduction in cost can be achieved if the pads are ofuniform construction, which brings up the problem that even small closetthe large pad, such as that shown in Fig. i, will have a higher rate ofvc-latilization than necessary with a correspondingly shorter To remedythis, I have provided the crease ii in the mounting i, where the saidmounting i may be folded backwards upon itself, producing the differentinsecticide shown in Fig. 2, which has a much slower volatilization ratethan the same pad had originally.

Though it has not been possible to exactly duplicate conditions for longenough periods to make a closer estimate, the generally slowed up rateof volatilization is thought to closely approximate five eighths of thatof a similar pad not folded. In other words, the same pad will lastnearly one and six-tenths the time'foided as unfolded. Ii torn apart andthe part to be saved is put into a waxed paper sack, a somewhat similarresult can be had at the expense of additional care and attention.

In Figs. 4 and 5 the broken lines I are intended to illustrate acontinuous layer of saturated air in the first instance and the resultof spacing in the second.

Having described my invention in what I now believe to be its best form,and explained the principle thereof, what I claim as new and desire tosecure by Letters Patent, is:

1. A fumigant pad comprising an elongated cardboard mounting memberformed with spaced dependent fingers thereon, said fingers carrying adeposit of vaporizable crystalline material thereon and of such uniformdimensions that when the card is folded upon itself, the fingers willfit spaces to produce a practically unbroken body with materially lowervolatilization characteristic than the unfolded card with spacedfingers.

2. An insecticide carrying pad, foldable mounting member formedcomprising a with spaced dependent fingers thereon, said fingerscarrying independent deposits of volatilizable material thereon ofuniform breadth, with spaces therebetween able to accept other fingerstherebetween when the said mounting member is folded upon itself, todecrease the number of spaces to slow the rate of volatilization.

FRED H. MAYER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,923,616 Dietmann Aug. 22, 19332,054,434 Mayer Sept. 15, .1936

